Liquid transport device providing diversion of capillary flow into a non-vented second zone

Claim 2

A liquid transport device comprising means defining a first capillary transport zone, said means including (i) a first set of opposing surfaces spaced apart a distance effective to provide capillary flow of introduced liquid, and (ii) flow-terminating means defining a flow-through width of said first zone; liquid access means for admitting liquid into said first zone; means for venting air entrapped in said first zone; and means defining a second, non-vented capillary transport zone having two spaced-apart ends, including: (a) means defining, at one of said ends and in one of said opposing surfaces, a diverting aperture located downstream from said access means and having (1) a width dimension which is greater than 0.4 of its length dimension, (2) a dimension extending parallel to said first zone flow-through width that is between about 0.65 and about 0.9 of the said flow-through width, and (3) a flow-through area greater than about 0.2 mm 2 ; and (b) a terminating surface disposed at the other of said ends of said second zone opposite said diverting aperture; the relationship of (i) the spaced-apart distance between said opposing first zone surfaces at said diverting aperture, to (ii) the distance between said opposing surface containing said diverting aperture and said terminating surface, being effective to insure that the liquid of said first zone enters said diverting aperture and contacts said terminating surface, before the flow of the liquid in said first zone surrounds said diverting aperture, whereby liquid flows to said terminating surface in response to capillary force even in the absence of venting means in said second zone.

Claim 3

A device as defined in claim 1, wherein at least one of said members is readily wetted by a liquid having a surface tension between about 25 and about 75 dynes/cm.

Claim 4

A device as defined in claim 1, wherein the surface of said first zone opposite to said diverting aperture is made of a material which forms a contact angle with said liquid of between about 60° and about 80°.

Claim 5

A device as defined in claim 2 or 3, wherein said spaced-apart distance is at least that defined by the equation h=150+0.87t.sub.o wherein h is said spaced-apart distance and t o is said distance of said second zone between said opposing surface and said terminating surface, in microns.

Claim 6

A device as defined in claim 1 or 2, wherein said diverting aperture is circular in shape.

Claim 7

A device as defined in claim 1 or 2, wherein a portion of said terminating surface is adhered to said opposing surface containing said diverting aperture.

Claim 8

A device as defined in claim 6, wherein said terminating surface is an exterior surface of an ion-selective electrode.

Claim 9

A device as defined in claim 7, wherein said ion-selective electrode comprises layers of materials adapted to assay for Cl.sup.⊖.

Claim 10

A device as defined in claim 1 or 2, wherein said spaced-apart distance at said first zone is less, at locations distal to said diverting aperture, than said spaced-apart distance at said diverting aperture, whereby the total amount of liquid required to fill said first zone is reduced.

Claim 11

A liquid transport device comprising means defining a first capillary transport zone, said means including (i) a pair of members having a first set of opposing surfaces spaced apart a distance effective to provide capillary flow of introduced liquid, and (ii) flow-terminating means defining a flow-through width of said first zone; liquid access means for admitting liquid into said first zone; means for venting entrapped air in said first zone; and means defining a second, non-vented capillary transport zone having two spaced-apart ends, including: (a) means defining, at one of said ends and in the opposing surface of one of said members, a diverting aperture located downstream from said access means and having (1) a width dimension which is greater than 0.4 of its length dimension, and (2) a transverse cross-section flow-through area greater than about 0.2 mm 2 ; and (b) a terminating surface disposed at the other of said ends of said second zone opposite said diverting aperture; the relationship of the spaced-apart distance between said opposing first zone surfaces at said diverting aperture, to the distance between said opposing surface containing said diverting aperture, and said terminating surface, and the relationship of said width of said first zone at said diverting aperture, to the dimension of said diverting aperture that extends parallel to said first zone flow-through width, being effective to insure that the liquid of said first zone enters said diverting aperture and second zone and contacts said terminating surface, before the flow of the liquid in said first zone surrounds said diverting aperture, whereby liquid flows under capillary forces to said terminating surface even in the absence of venting means in said second zone.

Claim 12

A liquid transport device comprising means defining a first capillary transport zone, said means including (i) a pair of members having a first set of opposing surfaces spaced apart a distance effective to provide capillary flow of introduced liquid, and (ii) flow-terminating means defining a flow-through width of said first zone; liquid access means for admitting liquid into said first zone; means for venting entrapped air in said first zone; and means defining a second, non-vented capillary transport zone having two spaced-apart ends, including: (a) means defining, at one of said ends and in the opposing surface of one of said members, a diverting aperture located downstream from said access means and having (1) a width dimension which is greater than 0.4 of its length dimension, and (2) a transverse cross-section flow-through area greater than about 0.2 mm 2 ; and (b) a terminating surface disposed at the other of said ends of said second zone opposite said diverting aperture; the relationship of the spaced-apart distance between said opposing first zone surfaces at said diverting aperture, to the distance between said opposing surface containing said diverting aperture, and said terminating surface, and the relationship of said width of said first zone at said diverting aperture, to the dimension of said diverting aperture that extends parallel to said first zone flow-through width, being effective to insure that the liquid of said first zone enters said diverting aperture and second zone and contacts said terminating surface, before the flow of the liquid in said first zone surrounds said diverting aperture, whereby liquid flows under capillary forces to said terminating surface even in the absence of venting means in said second zone.

Claim 13

A device as defined in claim 10, wherein at least one of said members is readily wetted by a liquid having a surface tension between about 25 and about 75 dynes/cm.

Claim 14

A device as defined in claim 10 or 11, wherein said diverting aperture is circular in shape.